The Topic: 
Simple Machines

Easier - A simple machine is a device that helps make work easier; a device that makes it easier to move something. Some simple machines are a wheel, a pulley, a lever, a screw, and an inclined plane.
Harder - Most machines consist of a number of elements, such as gears and ball bearings, that work together in a complex way. No matter how complex a machine, it is still based on the compounding of six types of simple machines. The six types of machines are the lever, the wheel and axle, the pulley, the inclined plane, the wedge, and the screw.
Background Information for Simple Machines from National Museum of Science and Technology, Canada
Here you can find the answers to some commonly asked questions about simple machines.
The Elements of Machines: Simple Machines from Leonardo's Workshop
Learn about devices that make work easier to do by providing some tradeoff between the force applied and the distance over which the force is applied. Also provides a brief introduction to uses of a gear, cam, crank and rod, chain and belt, and the ratchet.
Levers from Beakman & Jax
Play with levers and find out how work from the fulcrum to the load to the effort.
(Wait for second page to come)
Marvelous Machines
This website provides a series of experiments about simple machines: levers, wheels and inclined planes. They were developed for third grade students. (Comes up slowly)
After exploring some or all of the websites below, complete one or more of these activities:
Investigate Wheels with Your Bicycle. Go to PBS Teachersource's Mathematics of Bicycles I: Wheel Figure This Out website and use your bicycle to learn about the wheel.
Find Out How Stuff Works. Check out How Stuff Works. Look for a device that uses a simple machine as part of how it works. Create a poster showing how it works.
Gear Up with a Tricycle & Bicycle. Visit PBS Teachersource's Mathematics of Bicycles II: Gearing Up! site and follow the procedures there to learn a lot more about gears.
Complete a Simple Machines WebQuest. Follow or adapt the procedures found at one of these webQuest sites: 
1) Exploring Simple Machines by Paula Markowitz (Grade 4)
2) Simple Machines
3) Simple Machines WebQuest (Grade 4-6)
4) Simple Machines
5) Simple Machines Webquest
Complete an Online Simple Machines Activity. Learn more about simple machines by following the directions at A Time for Simple Machines. You may also want to test your knowledge at Gadget Anatomy.
Complete Some Simple Machine Experiments. Find lots of experiments at sites like Marvelous Machines and Motion, Energy and Simple Machines.
Websites For Kids
Simple Machine Page for Kids
This is a page on simple machines for kids with pictures.
Simple Machines (Part of a ThinkQuest project: E'Ville Mansion!
Learn about four simple machines ( Inclined planes, pulley systems, levers, and the wheel and axle). All are mechanisms that convert energy to a more useful form.
More Simple Machine Websites
Mechanisms and Simple Machines from Introduction to Mechanisms at Carnegie Mellon University
Here is advanced level material that covers inclined planes, gears, pulleys, and more.
Motion, Energy and Simple Machines by J.S. Mason
This site investigates Newton's Laws of Motion and the concepts of potential and kinetic energy. The concepts of force, friction, energy transfer, and mechanical advantage are explored as you build simple machines and investigate there operation.
Oh No Lego® Wedgies! from Weird Richard
Explore the wedge, the active twin of the inclined plane. It does useful work by moving. In contrast, the inclined plane always remains stationary.
Related Websites from Weird Richard:
2) Ladies and Gentlemen...The Inclined Plane!
3) Oh Goody, Even More on Gears!
3) Those Crazy Lego® Screws!
Simple Machines
This site houses a collection of over seventy photographs of common, everyday simple machines.
Simple Machines Demo (Pulley and Levers)
This demonstration explores the mechanical advantage of pulleys and levers and evaluates the concept of torque.
Spotlight on Simple Machines from "inQuiry Almanack" at Franklin Institute
Here you learn about simple machines that make work easier: inclined plane, lever, wedge, screw, pulley, and the wheel and axle.
Websites for Teachers
A First-Class Job
What happens when the position of the fulcrum on a first-class lever is changed?
Bicycles by J.P. Crotty from Yale-New Haven Teachers Institute
This is the site of a narrative unit plan that begins with the circle and proceeds to investigation of simple machines using the bicycle.
Sketching Gadget Anatomy at The Museum of Science
The idea for this lesson is that close observation and sketching lead to a better understanding of how machines work.
Simple Machines (Grades 3-4) by C. Huddle
These activities are designed to give students experiences in using simple machines.
Similar Websites:
2) Simple Machines (Grade 3) by L. Wilkins
3) Simple Machines (Grades 4-8) by B. Campbell
4) Simple Machines
5) Simple Machines at Teachers.Net
6) Simple Machines (Grade 3)
7) Simple Machines Webquest
Simple Machines
Research and Informational site to links.
Simple Machines
A major component of this lesson is a simple machines scavenger hunt.
Work Is Simple With Simple Machines
Students participating in this project will investigate simple machines and their usefulness in everyday life.
simple machine
wheel and axle
moveable pulley
inclined plane
fixed pulley
compound machine
motion transfer
change distance
Rube Goldberg
energy transfer
Created by Annette Lamb and Larry Johnson, 1/00. Updated by Nancy Smith, 6/02.